package com.mcj.managementSystem.utils;

import cn.hutool.core.date.DateUtil;
import cn.hutool.core.util.StrUtil;
import com.auth0.jwt.JWT;
import com.auth0.jwt.algorithms.Algorithm;
import com.mcj.managementSystem.entity.User;
import com.mcj.managementSystem.service.IUserService;
import org.springframework.stereotype.Component;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;

import javax.annotation.PostConstruct;
import javax.annotation.Resource;
import javax.servlet.http.HttpServletRequest;
import java.util.Date;

@Component
public class TokenUtils {
	
	private static IUserService staticUserService;
	
	@Resource
	private IUserService userService;
	
	@PostConstruct
	public void setUserService() {
		staticUserService = userService;
	}
	
	/**
	 * 生成token
	 *
	 * @return token
	 */
	public static String genToken(String userId, String sign) {
		return JWT.create().withAudience(userId) 							// 将 user id 保存到 token 里面,作为载荷
				.withExpiresAt(DateUtil.offsetHour(new Date(), 2)) 	// 2小时后token过期
				.sign(Algorithm.HMAC256(sign)); 							// 以 password 作为 token 的密钥
	}
	
	/**
	 * 获取当前登录的用户信息
	 *
	 * @return user对象
	 */
	public static User getCurrentUser() {
		try {
			HttpServletRequest request = ((ServletRequestAttributes) RequestContextHolder.getRequestAttributes()).getRequest();
			String token = request.getHeader("token");
			if (StrUtil.isNotBlank(token)) {
				String userId = JWT.decode(token).getAudience().get(0);
				return staticUserService.getById(Integer.valueOf(userId));
			}
		} catch (Exception e) {
			return null;
		}
		return null;
	}
}
